Media Browser Upload: Photos Library Never Loads

[Mr_Brightside_@]

I am running Safari Version 14.0.1 (14610.2.11.51.10), all Mojave and security updates applied.

When attempting to upload photos from my Photos library via Upload > Media Browser > Photos, my library never loads. I either get a message saying Loading images... (I have left this window open for hours) or Open Photos to view. Either way, my library never loads.
iCloud Photo Library is enabled, and this issue affects Macs that have Download Originals enabled, and ones that don't (same Apple ID). The Photos library is set as the system library.

Anyone else experiencing this? Any fixes?

 

[Mr_Brightside_@]

It seems to be documented here, but oddly, my 'normal' uploads sometimes work.

macOS Security Update Archives - Mr. Macintosh

mrmacintosh.com

 

[Mr_Brightside_@]

Fixed by reverting to Safari 14.0